Type action system for typewriting machines



June 15, 1954 H. c. YAEGER TYPE ACTION SYSTEM FOR TYPEWRITING MACHINES 2Sheets-Sheet 1 Filed Dec. 11, 1951 lNl ENTOR HARM QC. MEGER ATTORNEY H.c. YAEGER TYPE ACTION SYSTEM FOR TYPEWRITING MACHINES Filed Dec. 11,1951 June 15, 1954 2 Sheets-Sheet 2 INVENTOR. HARRY C. VAEGER PatentedJune 15, 1954 Harry G. Yaeger, West Hartford, 001111., assignor toUnderwood Corporation, New York, N. Y., a corporation of DelawareApplication December 11, 1951, Serial No. 260,960

6 Claims.

This invention relates to typewriters and the like and more particularlyto type-action systems thereof having the type bars pivoted in anarouate array on a segment to strike at a common typing point, andwherein case shift is effected system with the direction or path of caseshift.

Accordingly, a general object of the invention is to provide, in asegment-shift, hammer typebar kind of typewriter, an arrangement of thetype-action system and a case-shift guiding 6 by shifting the type-barsegment. means coordinated therewith, which arrange- In type-actionsystems to which the invention ment aifords a substantial angularrelation be pertains, each type bar is actuated by a straight tween thequiescent type bars and their underlink or pull rod extending forwardlybeneath the lying pull links.

- type bar from its point of connection to an oper- 1: Another object isto provide a segment caseating arm of the type bar. In segment-shiftshift arrangement coordinated with an improved typewriters the segmentis usually shifted in a type-action system, the organization and arplane that is tangential to the platen at the rangement of the elementsof the latter having typing point. In order not to transmit any pertheadvantage of accommodating an appreciably ceptible motion to the keylevers nor change the inclined segment for purposes such as to secure aoperating relation of the parts during case shifttyping point well abovethe level of the platen ing, these pull links are usually arrangedsubaxis, the related tilting of the type bars being stantially at rightangles to said plane of shift. readily feasible without howevernecessitating Each pull link is connected at its forward end any majorchange in the arrangement of other to an actuating member, which in theUndertype-action elements, particularly the substanwood typewriter takesthe form of a sub-lever, as tially horizontal disposition of theunderlying pull exemplified in Helmond patent, No. 2,072,878, for links.manual typewriters, and in Yaeger patent, No. In prior segment-shifttypewriters, the neces- 2,254,764, for power-operated typewriters. AsSity of shifting the S t dow w d to effect shown in said patents, thetype-action pull links case shift presented a condition which, becauseassume substantially horizontal positions in acof the substantiallyparallel close relation of the cord with the substantially verticalplane of case q i n yp bars nd h r p links, m d i shift and aretherefore at or very close to a, impracticable to provide the requisitedust shelf parallel relation with the horizontal type bars. on thesegment, because of the lack of sp In typewriters wherein the segmentshifts in a l r f h lin n ary to ommodate vertical plane, this is duemainly to the fact that bowed or arched type bars required to clear thethe typing point is at a level with the platen axis, dust Shelf. and theplane of shift is required to be tangen- A further object, therefore,resides in the protial with the platen at said point. Should it bevision of a correlated type-action system and S edesired to have thetyping point appreciably merit shift arrangement, by which adequat iabove the level of the platen axis, it then becomes ing between the typebars and their straight necessary to correspondingly tilt the type-barOperating links is had, 50 that the downwardly segment so that its planeof shift is tangential at ed typ bars, arched 50 a 110 lear a saidraised typing point, the type bars at rest segment-carried dust shield,will not clash with being also correspondingly inclined. The reorobstruct proper operation of the type-acti0n sultant inclination of thetype bar dissolves its lin sparallelrelation with the pull link, unlessthe Other objects will be in p t bv s and in position of the latter isalso to be substantially part Particularly pointed out as the followingchanged. Thus, if it is necessary to discontinue scription of a P efe edembodiment of the nthis substantially parallel relation between theVention p ce type bar and its operating link, either to raise In e d withe typing point appreciably above the level of Figure l is a sectionalView taken on a medial the platen axis without changing the horizontalplane iore-and-aft of the typewriter embodying position of the pulllink, or to afford an apprethe invention, and, showing a middle typeaction ciable angular space relation between these parts and anothertype action at the far side of the for reason such as to accommodate atype bar typeaction system, that is arched to clear a dust shield on theseg- Figure 2 is a plan view of the type-action ment, this disturbs thefundamental relation of system taken on a plane 22 of Figure 1, but thetype-action elements and this in turn mateviewing only the half of thetype-action system rially upsets the inter-relation of the type-actionopposite that shown in Figure 1, and

Figure 3 is a front view of the type-action system taken on a line 3-3of Figure 2.

Except for the relative arrangement of several of the series oftype-action parts as hereinafter explained, the type-action systemforming the illustrated embodiment of the invention conformssubstantially to that described and claimed in the Helmond patent, No.2,072,878. A brief description of the type-action system herein willtherefore sumce. Referring to Figure 1 a series of key levers 5, theforward key-equipped portions of which are omitted, are each pivoted ona common fulcrum rod in a crossbar 6 of the typewriter. At a pointintermediate its end, each key lever is connected by a link 1 to a sublever 3. The sub-levers 3 are all pivoted on a common fulcrum rodretained in a crossbar it.

A series of type bars H are each pivoted in an arcuate array on a pivotrod [2 in the segment l3. Each type bar ii has an operating arm Itextending rearwardly and downwardly from the pivot i2 and having aconnection i5 to a pull link IS, the other end of which is connected atH to a corresponding one of the sub-levers 8.

In view of the arcuate arrangement of the type-bar pivots 42, theconnections 15 to the links it also present a curved or arcuateformation, see Figure 3. The lower portion of each sublever B, wheresame is pivoted in the crossbar iii, is disposed vertically in the planeof the associated key lever 5. This makes the row of sub levers 8appreciably wider, transversely of the typewriter, than the array of thetype-bar-link connections 15. Therefore, the successive sublevers 8 arebent to offset their upper ends at gradually increasing extents, rangingfrom the center type action outward, so that said ends at which thelinks id are connected are close to the plane of the correspondingoperating arms i of the type bars. To assure a uniform length for thelinks I6, and to attain certain operating advantages incidental to caseshifting, the upper end portions of the sub-levers B forming the linkconnections I? present an arcuate array conforming substantially to thatof the link connections 15 and circumjacent thereto, as shown in Figure3, and each of said end portions is disposed in a plane radiating fromthe typing point as later described. As described in detail in saidHelmond patent, the points of connection of the links 1 to thesub-levers 8 are arranged at gradually increasing distances from thesub-lever pivot, ranging from the center type action outward, to assurea uniform stroke for each type bar I 5. Likewise, the points ofconnection of the links I to the key levers 5 are at graded elevationsincreasing from the center outward.

As afore-stated, the sub-levers 8 may be either manually operated, asshown in said Helmond patent, or may be power operated, for example, asshown in said Yaeger patent, No. 2,254,764. In its broader aspect thesub-lever 8 of each type action constitutes an actuating member thereof,in that the manner of actuating the pull link l6, whether by a sub-leveras shown, or by other actuating means, is not important to the practiceof the invention. It is however essential that the connection points llof the actuating members be positioned to accommodate the prescribedarrangement of the links, as later described.

The type bars ll when inactive assume the positions shown in Figure 1with their forward ends lying against a usual type-bar rest, not shown,which is supported on the segment I3 to move the entire type-bar baskettherewith in case shifting. The type bars II are guided by the usualradial slots IS in the segment, Figure 3, to strike at a common typingpoint indicated at T in Figures 1 and 3. The usual type guide, notshown, may serve to further guide the type so as to strike accurately atsaid point. It may be here noted, with reference to Figure 1, that thetyping point T in the embodiment shown is at the point of tangency of aline in a central vertical plane fore-and-aft of the typewriter, tangentwith the platen 20 and extending through or relatively close to the axisof the pivot rod i2. Said typing point is further indicated as being atthe intersection of a construction line A with the periphery of theplaten and passing through the platen axis.

Erasures made on the work sheet resting against the platen 20 result inmuch of the eraser dust falling against the segment 13 and lodging to alarge extent in or about the pivot slots is where an accumulationbecomes detrimental to proper operation of the typewriter. the eraserdust from reaching the type bar pivotal mounting, a shelf-likeprojection or dust shield 22 is provided. This dust shelf is just abovethe array of pivot slots 58 and may be arouate and concentric with thepivot rod 12. In order to clear the dust shield 22 as the type strikesthe platen, the type bar I l is substantially arched as indicated at 23.Because of the closeness of the dust shelf 22 to the pivotal mounting ofthe type bars, it is necessary that the arched portion 23 start abruptlyjust beyond the type-bar pivot, at which portion, also, a shoulder 24 ofthe type bar is arranged to engage a universal bar 25 for operating theletter-feed mechanism. The abruptness and close proximity of the archedportion 23 to the type-bar pivot 12 makes the problem of clearancebetween each type bar and its pull link :6 more acute, since the outeredge of the type bar at said arch bows out appreciably from the body ofthe type bar.

In the embodiment of the invention illustrated, the means for guidingthe segment l3 for caseshift movement, except as to certain features ofarrangement hereinafter set forth, is like that described and claimed inthe Helmond patent, No. 2,306,604, to which reference is had for detailsnot shown herein. As is the usual practice, the segment is is normallysuspended by spring means, not shown, in its upper position in which thetype of the lower case on the type bars II are adapted to strike thetyping point T, and from which the segment is shifted downwardly tocause the other or uppercase of type to strike at said point. Thesegment 13 is secured to a segment frame 21, the upper portion of whichis guided for case-shift movement by a ball-andraceway unit 28 at eachside of said frame. Said units each comprise raceways respectively onthe segment frame and on a member 29 of the typewriter mainframe. Thetwo balland-raceway units 28 constitute guiding means for the upper partof the segment, causin said part to move in a path indicated by the line30 in Figure 1, as later described.

The segment frame 2'! has at each side thereof a downwardly reaching leg3|, Figure l, on each of which a roller 32 is rotatably mounted. Eachroller 32 rides between front and rear guide faces 33 of a member 34,and each of said members is secured to a crossbar 35 of the typewriter.The rollers 32, the members 34 and the crossbar 35 constitute a guidingmeans for the lower portion of the segment, by which the axis of saidroller To prevent v is caused to follow a path indicated by the line 35,later described.

To assure equal movement of each lateral portion of the segment frameduring case shifting, a bail 38 is provided, a cross-shaft 39 of whichrigidly connects the two arms 40 and is pivoted at M on the typewritermainframe. Since the segment frame 2? moves in a path not concentricwith the axis of pivots ll, a sliding connectionbetween the bail arms 46and the segment frame is provided. This may take the form of a shoe 42rockably secured to each bail arm and slidable in a groove in eachlateral edge of the segment frame. Thus, the bail 38 will cause thesegment frame to case shift with a parallel-motion and yet will notinfluence the direction of case-shift movement, this being the combinedfunction of the upper guiding means 28 and the lower guiding means 3235.

The mechanism for actuating the type-bar segment i3 in case shift may beof any suitable kind. That shown herein in Figure 1 comprises a shiftkey lever d3 similar to the key lever 5 but having a hook portion Mwhich engages a stud 45 on a shift arm &5. The shift arm 46' ispivotally mounted at its forward end, the other end being operativelyconnected by a link 4? to the leftward leg 3% of the segment frame 21.Depressing shift key lever 43 will cause the shift 5 to swing clockwiseabout its pivot and thus the type-bar segment downward.

The present invention provides a type-action system arrangement and asegment case-shift guidingmeans coordinated therewith, by which anappreciably angular spacing is afforded between the type bar I l as aWhole and its pull link it. From one aspect, this enables disposing thetype-car segment at an appreciable angle consistent with a typing pointthat is substantially above the level of the platen axis, and yetpermits the links if? to remain at about their horizontal positions. Orif desired, the principles of the invention. will accommodate anarrangement of the pull links it that inclines substan-' tiallydownwardly from the connection l5 of the type bar, while maintaining thetype bar in its previous horizontal position and the segment in itsapproximately vertical position consistent with a typing point that isabout at the level of the platen. The arrangement of the elements of thetype-action system, particularly the segment l3 and the links l6 asillustrated in Figure 1, is in effect a combination of these features ofarrangement. That is, the segment [3 is disposed at an appreciable anglefrom the vertical, and the links are in lined somewhat from thehorizontal.

From another aspect, the provision of an ap-' preciable angular spacingbetween the type-bar lever and its pull link it has the advantage ofaccommodatin bowed or arched type bars and thus enables the use of thedust shelf 22, in a segment-shift typewriter. As before mentioned, theclose proximity of the arched portion 23 to the type-bar pivot l2 causesthe type bars, particularly at or near the center of the machine, toproject into the region heretofore occupied by the pull links in theirsubstantially parallel relation to the type bars.

As shown in Figure l, the link connections 5 to each of the type-baroperating arms it move in a generally up-and-down direction during caseshifting, and this movement in turn causes each of the straight pulllinks it to oscillate. between the two positions shown respectively infull and dot-and-dash outline. The construction line B relates only tothe link it of the medial; type action. Said line bisects the angle of.vibration of that link It and thus indicates the center-line ofoscillation of said link, intersecting the pivotal point I? andextending rearwardly therefrom. Line B is a construction line similar toline B except that it relates to the link [6 associated with theoutermost. type action of the system. The construction line B shown inFigure 2 is the same as the line 13 shown in Figure 1 except that itrelates to the outermost type action at the opposite or right side ofthe typewriter. In Figure 3 the line B is a construction line like lineB but relates to a type action intermediate the medial and outermosttype actions' It will be recalled with reference to Figure 1 that theconstruction line A extends from the typing point T rearwardly throughthe axis of the platen 20. to Figure 2 that said line A is in a centralvertical plane fore-and-aft of the typewriter. Said line A extendsrearwardly to a point of convergence C, at which point the lines B, Band 1% relating to the links it of all the type actions converge. Itwill now be seen, in view of. the arcuate arrangement of the linkconnections I? to the sub-levers 8, that the lines B, B and B extendingfrom all of the connections l1 to the point of convergence C,collectively form a conical contour. The apex of the cone thus formed isat the point C and the line A is the center-line or axis of the cone.

A horizontal line I), Figure 2, at right angles to the line A andpassing through the point of convergence C, defines an axis which formsthe basis for coordinating the case-shift guiding means with thetype-action system and with the typing plane on the platen. That is tosay, the means for guiding the segment it in case shift is so arrangedwith respect to the pull links l5 of all of the type bars ii that thepoints of connection move in prescribed paths such as will avoid thetransmission of any motion to the sublevers 8 and thence to the keylevers 5. The arrangement of the segment-guiding means further assuresthat both cases of type on the type bars I! will approach the typingpoint, to strike the platen, on a line radial with the axis of theplaten at said point.

To accomplish this coordination, the segment 53 during case shift movesin an arcuate or cylindrical path, the curvature of which is concentricwith the axis D which, as stated, coincides with point of convergence C.Since the shift movement of the segment is determined by the upperguiding means 28 and the lower guiding means: 32-32%, it follows thatthe paths of travel generated. by these guide means, respectively, areconcentric with said D. That is, with re spect to the two upper guideunits 23 at the sides of the segment, the line of travel 3d determinedby each unit 28 is an arc struck from the center or axis D. Likewise,with respect to the two low or guide units 3235 at the opposite sides ofthe segment frame, the line of travel 36' determined by the guide faces33 of each lower unit:

is an arc, the center of which is the axis D.

By causing the segment l3 to case shift in a cylindrical path concentricwith the axis D on which-the point C lies, the connection points l5 ofeach pull link IE will be caused to move in paths also concentric withthe axis D. In that the center-line of oscillation B, considering onlythe central type action for example, radiates It will be noted withreference.

from the point C, it follows that the path taken by that connection I issubstantially normal to, or at right angles with, said line B. It willbe seen that said path coincides substantially with an arc struck fromthe point ll, through the upper and lower positions of point 15, andthat therefore practically no motion will be transmitted through link 16during or incidental to the caseshift movement of point l5. With regardto the typing point T on the platen 20, it follows that, because thesegment moves in a path concentric with the axis D, and because of thefact that the line A passing through the platen axis and the typingpoint radiates from the point C on axis D, both the upper and the lowercase of type will approach the platen on the radial line A and will meetthe platen on a plane tangential thereto at the typing point.

Considering the very short extent of caseshift movement, about onequarter inch in most typewriters, particularly in relation to the largeradius of curvature of the path of point l5, tak ing the medial typeaction for example, it will be seen that said path as generated by theupper and lower guide means respectively may be in a straight line. Itis necessary, however, that said straight line path be at right anglesto the line B. This result will be had if the path 36 described by eachlower guide means 3235, instead of being a curve from the axis D, be ona straight line which forms a chord of said arc, intersecting the upperand lower points defining the two positions of the axis of roller 32.The same applies as to the path 35 of the upper guide means 23. That is,instead of being curved on the axis D, said path may lie in a straightline which forms a chord of the arc described by said curve. By havingthe point move in a straight line path, related to the axis D asdescribed, said path will coincide more closely with the arc struck frompoint ll.

While the above description is confined to the effect of the arrangementof the case-shift guiding means on the central type action, particularlywith reference to the link 16 and the construction line B thereof, itwill be apparent that a similar eifect is had for all the type actions.That is, the points l5 of the other links l6 throughout the entiretype-action system will move in like paths having a similar relation totheir respective construction lines B and B since all said constructionlines converge on the point C and since said point is on the axis D uponwhich the path of movement of the typebar segment is based.

Having thus described the invention, what is claimed is:

1. In a typewriter type-action system, a cylindrical platen, a series oftype bars each having an operating arm, means including a segmentpivotally mounting said type bars to strike at a common typing point onthe platen, a series of straight pull links connected respectively tosaid type-bar operating arms, the arrangement of said operating arms andsaid pull links with respect to the body of the type bars when inactivebeing such that said pull links are relatively close to and beneath thebody of the corresponding type bars, means for guiding said segment incaseshift movement, and a series of actuating members connected to theforward ends of said pull links, said actuating members beingnon-caseshiftable, said pull links therefore oscillating during caseshift to accommodate the shift movement of the type bars, each linkhaving a construction line extending from its point of connection to theactuating member and bisecting the angle of oscillation, the arrangementof all the links being such that their construction lines convergesubstantially at a common point, said point of convergence lying in afore-and-aft center-line of the typewriter extending from the typingpoint and intersecting the axis of said platen, said point ofconvergence also lying in a horizontal axial line normal to saidcenter-line, said case-shift guiding means being adapted to guide thesegment in a path substantially concentric with said axial line.

2. In a typewriter type-action system, a cylindrical platen, a series oftype bars each having an operating arm, means including a segmentpivotally mounting said type bars in a curved array to strike at acommon typing point on the platen, a series of straight pull linksconnected respectively to said type-bar operating arms, the arrangementof said operating arms and said pull links with respect to the body ofthe type bars when inactive being such that said pull links arerelatively close to and beneath the body of the corresponding type bars,means for guiding said segment in case-shift movement, and a series ofactuating members connected to the forward ends of said pull links, saidactuating members being non-case-shiftable, said pull links thereforeoscillating during case shift to accommodate the shift movement of thetype bars, each link having a construction line extending from its pointof connection to the actuating member and bisecting the angle ofoscillation, the arrangement of all the links being such that theconstruction lines thereof collectively define a conical contour, theapex of the cone being in a center-line of the typewriter extendingrearwardly from the typing point and intersecting the axis of saidplaten, said cone apex substantially coinciding with a horizontal axialline normal to said center-line, said case-shift guiding means beingarranged to guide the segment in a path substantially concentric withsaid axial line.

3. In a typewriter type-action system, a cylindrical platen, a series oftype bars each having an operating arm, means including a segmentpivotally mounting said type bars in a curved array to strike at acommon typing point on the platen, a series of straight pull linksconnected respectively to said type-bar operating arms, the arrangementof said operating arms and said pull links with respect to the body ofthe type bars when inactive being such that said pull links arerelatively close to and beneath the body of the corresponding type bars,separate means for guiding respectively the upper portion and the lowerportion of the segment in case-shift movement, and a series of actuatingmembers connected to the forward ends of said pull links, said actuatingmembers being non-case-shiftable, said pull links therefore oscillatingduring case shift to acc0mmodate the shift movement of the type bars,each link having a construction line extending from its point ofconnection to the actuating member and bisecting the angle ofoscillation, the arrangement of all the links being such that theirconstruction lines converge substantially at a common point, said pointof convergence lying in a center-line of the typewriter projectingrearwardly from the typing point and intersecting the axis of saidplaten, said point of convergence also lying in a horizontal axial lineat right angles to said center-line, each of said segment guiding meansdefining paths of movement for the respective portions of the segmentthat are cylindrical and concentric with said horizontal axial line,

4. In a typewriter type-action system, a cylindrical platen, a series oftype bars each having an operating arm, means including a segmentpivotally mounting said type bars in a curved array to strike at acommon typing point on the platen, a series of straight pull linksconnected respectively to said type-bar operating arms, the arrangementof said operating arms and said pull links with respect to the body ofthe type bars when inactive being such that said pull links arerelatively close to and beneath the body of the corresponding type bars,separate means for guiding respectively the upper portion and the lowerportion of the segment in case-shift movement, and a series of actuatingmembers connected to the forward ends of said pull links, said actuatingmembers being non-case-shiftable, said pull links therefore oscillatingduring case shift to accommodate the shift movement of the type bars,each link having a construction line extending from its point ofconnection to the actuating member and bisecting the angle ofoscillation, the arrangement of all the links being such that theirconstruction lines converge substantially at a common point, said pointof convergence lying in a center-line of the typewriter projectingrearwardly from the typing point and intersecting the axis of saidplaten, said point of convergence also lying in a horizontal axial lineat right angles to said center-line, each of said segment guiding meansdefining paths of movement for the respective portions of the segmentthat are each normal to a plane intersecting said horizontal axial lineand midway of the limits of case shift at each portion.

5. In a typewriter type-action system, a cylindrical platen, acase-shiftable segment, a series of type bars pivoted in an arcuatearray on said segment to strike at a common typing point on the platen,said segment having a dust shelf projecting forwardly therefromcircumjacent the arcuate type-bar pivot array, each of said type barsbeing arched so as to clear said dust shelf when the type bar types,each of said type bars having an operating arm extending rearwardly anddownwardly from its pivot, a series of sublevers having upstanding leverarms forward of the type-bar pivots, a series of straight pull linksconnecting the type-bar operating arms and the sub-lever arms, said pulllinks being each disposed at an appreciable angle from the body of thecorresponding type bar so as to afford space for the arched portion ofthe type bar, said sublevers being non-case-shiftable, said pull linkstherefore oscillating during case shift to accommodate the shiftmovement of the type bars, each said link having a construction lineextending rearwardly from its point of connection on the sub-lever armand bisecting the angle of oscillation, the arrangement of all the linksand sublever arms being such that the construction lines of the linksconverge substantially at a common point, said point of convergencelying in a centerline of the typewriter extending rearwardly from thetyping point and passing through the axis of the platen, said point ofconvergence being in a horizontal line normal to said center-line, andmeans to guide said segment for case-shift movement in a cylindricalpath the axial center of which coincides substantially with saidhorizontal line.

6. In a typewriter type-action system, a cylindrical platen, acase-shiftable segment, a series of type bars pivoted in an arcuatearray on said segment to strike at a common typing point on the platen,said segment having a dust shelf projecting forwardly therefromcircumjacent the arcuate type-bar pivot array, each of said type barsbeing arched so as to clear said dust shelf when the type bar types,each of said type bars having an operating arm extending rearwardly anddownwardly from its pivot, a series of sublevers having upstanding leverarms forward of the type bar pivots, a series of straight pull linksconnecting the type-bar operating arms and the sub-lever arms, said pulllinks being each disposed at an appreciable angle from the body of thecorresponding type bar so as to afford space for the arched portion ofthe type bar, said sub-levers being non-case-shiftable, said pull linkstherefore oscillating during case shift to accommodate the shiftmovement of the type bars, each said link having a construction lineextending rearwardly from its point of connection on the sub-lever armand bisecting the angle of oscillation, the arrangement of all of thelinks and sub-lever arms being such that the construction lines of thelinks collectively define a conical contour, the apex of which is in acenter-line of the typewriter extending rearwardly from the typing pointand passing through the axis of the platen, and means to guide saidsegment for case-shift movement in a generally cylindrical path theaxial center of which is on a horizontal line transverse of thetypewriter and at or near said conical apex.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,034,554 Yaw Aug. 6, 1912 1,568,736 Hokanson Jan. 5, 19262,184,736 Dobson Dec. 26, 1939

